Historian D. M. Giangreco examines the historical precedents for an enemy offensive tied to the upcoming report by Gen. Petraeus on the Surge in an essay on the History News Network:
Five times within the last 100 years, the US Armed Forces have had direct --- and painful --- experience with enemies who have tried to turn around a deteriorating situation by lashing back in one last, massive assault.
The list of presidents and their military commanders who have faced these crises reads like a who's who of recent American history: Woodow Wilson and General John "Blackjack" Pershing; Franklin Delano Roosevelt and General Dwight D. Eisenhower; Harry Truman and Admiral Chester A. Nimitz, then General Douglas MacArthur; and finally, with less happy results almost four decades ago, Lyndon Baines Johnson and General William Westmoreland.
This pattern is so well-established that we should discount in advance any such move as anticipated and normal, not "proof" of failure of the surge, which the left will undoubtedly portray it to be. Now is the time to warn that this is to be expected, and that previous American leaders got then country's support, at least until LBJ. The frightening thing, of course, is that Tet was a military disaster for the enemy (as the Surge is proving to be a victory for us), but that the press sold the public on a counter-factual interpretation.